// Copyright 2017 The LUCI Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package common

import (
	"fmt"
	"net/url"
	"time"
)

const (
	day  = 24 * time.Hour
	week = 7 * day
)

// must be sorted by descending.
var units = []struct {
	value  time.Duration
	symbol string
}{
	{week, "w"},
	{day, "d"},
	{time.Hour, "h"},
	{time.Minute, "m"},
	{time.Second, "s"},
	// no need for smaller units
}

// DurationString returns a nice duration string. Supports days and weeks.
func DurationString(d time.Duration) string {
	for _, u := range units {
		if d >= u.value {
			return fmt.Sprintf("%.2f%s", float64(d)/float64(u.value), u.symbol)
		}
	}
	return "0"
}

// PathEscape escapes the string so it can be safely placed inside a URL path segment.
// TODO(nodir): remove, when native url.PathEscape is available on AppEngine.
func PathEscape(s string) string {
	u := url.URL{Path: s}
	return u.EscapedPath()
}
